Google will introduce new technology controls to thwart people using blogs to manipulate rankings in its search results.

Otherwise known as "link" or "comment spam," the ruse is as old as Web marketing. Such Web site promoters use the comment form on forums, blogs or any Web page to place or gain a link pointing back to their own Web site. And because Google and other search engines tabulate search results in part by a Web page's link popularity with other sites, the trick can boost a site's ranking--and more importantly, traffic. It can also produce irrelevant search results.

In the age of blogging, the problem has grown acute because publishers have little recourse to stop outsiders from littering their comment forms with bogus links, short of shutting them down or inserting password protections.

Late Tuesday, Mountain View, Calif.-based Google plans to detail in its own blog a new tactic for blocking link spammers, according to a company representative.C|net